Busbar current capacity


MASSIVE restock of EV Batteries at www.batteryhookup.com 5% coupon "POWERWALLS"

Shorty

Member
Joined
Jun 8, 2020
Messages
30
I am fusing each cell to internal bus bars, the layout I have in mind is shown here:


image_kroiab.jpg


Each series cell is capable of 88A continuous, but the max load the system I am making would put on the cells is about 51A, and usually significantly lower than this. I would like to build in overheads however so I was thinking to spec the busbars to carry the full 88A.

I just wanted to check however that I was correct to think that each busbar between each series group needed to be able to carry the full 88A?

Assuming they do, I then used the following table:
https://www.powerstream.com/Wire_Size.htm

To get a cross sectional area required. So for a 10mm width and 1mm thick bar the "amps for chassis wiring" would be a bit under 89A.

So would a 10x1mm busbar with each cell individually fused be correct for this?
 

Korishan

Moderator
Joined
Jan 7, 2017
Messages
6,880
Yes, the interconnects between parallel groups carry the full current of the whole battery.

Capacity is the sum of the cells in parallel
Voltage is the sum of the cells in series
Ampacity is full load across the whole battery, only shared by cells in parallel (ie, 10A, 50 cells in parallel, each cell is outputting 0.2A)
 

Shorty

Member
Joined
Jun 8, 2020
Messages
30
Great, so I am speccing the busbar to carry the right kind of current. So can I use the cross sectional area from the powerstream table to correctly gauge the size of my busbars? (as this table is a wire table, I want to check this translates to a rectangular cross section)
 

Korishan

Moderator
Joined
Jan 7, 2017
Messages
6,880
Yeah, cross sectional is the same regardless of shape.
 
Top